Summertime, and the Targa is stalling
 

I have been trying to figure out for a while why my '77S suddenly starts stalling. Somewhere in this forum somebody related it to the AC operation.

Normally when I let off the gas, the revs drop to about 800 then rise to idle at 950. However when my AC is on, revs drop to 300 and the car stalls. It restarts right away.

I did the simple "spray carb cleaner" check for leaks and found only one small one.

So it must be the decel valve. I checked with CIS expert Jim Williams (CIS Primer ) and he indicated that on my car there is an adjustment screw on the top. Before I fooled with it, I thought I would get a sanity check here.

Has anyone tried adjusting the decal valve?
Any other suggestions?

Frank

P.S. Don't you California guys tell me to just remove the AC. It is 90 degrees and 90 % humidity here.

Frank,

Try these things:
Lean your mixture by 1/16 turn. Raise your idle (w/o air on) to just over 1000. Did you fix the air leak you found?

See if that works. If it is better but not quite right go 1/16 leaner, but no more. Idle @ 1000+.

If those don't work, then adjust the decel valve. You'll have to work by trial and error there to get the right setting.

Good luck and let us know what works.

Sure enough it was the decel valve. I got it adjusted today and the problem is fixed.

Frank

Frank,

Can you tell us how the adjustment was done. Say, from above, which direction was the nut turned, how much, and anything else that was done.

Paul,

I believe that SC engine has a different Decel valve than my '77. Our host shows the a part for '78 - 83. There is a CIS site on Rennlist (Jim's CIS Primer) that shows the difference.

I stopped to ask the guy who rebuilt my engine how to adjust it. He just went out and adjusted it for me. So I don't have the details of what he did.

My Decel valve is bell shaped on the left side of the air intake; I can see it with the air induction in place. There are two nuts (13mm & 7mm). Loosen the larger one, then adjust the smaller one a partial turn. My mechanic adjusted it, then revved the engine, adjusted it again and that was it.

No charge too! :) Hope that helps!